Rotary joint of articulation prosthetic implement having rotating load setting means, articulation prosthetic implement using the rotary joint and method of making articulation prosthetic implement

ABSTRACT

A method of manufacturing an articulation prosthetic implement includes the steps of previously manufacturing a on-way clutch covered and fitted with a metal bush, the metal bush covered and fitted with a synthetic resin bush, and the synthetic resin bush covered and fitted with a brake bush; covering and fitting a rotary shaft of an outer member with flanges at either end, having a rotary shaft at the inner side and an annular depression around the rotary shaft, with the one-way clutch having the three bushes; fitting a cylindrical projection of an inner member having flanges at either end into the annular depression of the outer member located outside the brake bush; screwing or bolting a stopper for controlling the range of rotary shaft rotation to an inner projection of the rotary shaft; fitting one articulation protecting member of the articulation prosthetic implement to the flange of the inner member from the surface side of the inner member; and fitting the other articulation protecting member of the articulation prosthetic implement to the flange of the outer member form the surface side of the outer member.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Divisional of U.S. patent application Ser. No.11/007,201, which was filed on Dec. 9, 2004.

BACKGROUND OF THE INVENTION

The present invention relates to the improvement of a rotary joint of anarticulation prosthetic implement having a rotating load setting means,an articulation prosthetic implement using the improved rotary joint,and a method of making (assembling) the articulation prostheticimplement. The present invention is effective as an articulationprosthetic implement for rectification of clubfoot in particular. Thatis, it can be effectively used for an articulation prosthetic implementconfigured in that one articulation protecting member out of verticallyadjoining articulation protecting members is rotatable against the otherarticulation protecting member about the axial center in a directionvertical to the adjoining direction.

Clubfoot (talipes equinovarus) is a foot in a state such that the footturns inward causing the sole to be faced inward, making it unable tocontrol the ankle, and the toe tip side (hereinafter called foot tip)droops downward, and the person is liable to stumble as the foot tiptouches the ground in walking, thereby causing hindrance to the walkingfunction.

And, for preventing such stumbling during walking, generally employed isa method that the foot tip is rectified upward in order to prevent thefoot tip from drooping downward, and as an articulation prostheticimplement (lower limb implement) to achieve the purpose, various typeshave been conventionally proposed. As shown in FIG. 7B, a normal stateis such that the foot is positioned (shown by solid line) in parallel tothe horizontal direction perpendicular to the leg being parallel to thevertical direction, and in that condition, when the foot is moved upwardabout the ankle bone as shown by imaginary line (chain double-dashedline), it is called back flexion, and when moved downward, it is calledbottom flexion.

In the case of a conventional articulation prosthetic implement, forexample, it is configured in that a lower articulation protecting memberis rotatably connected to a vertically adjoining upper articulationprotecting member, and the lower articulation protecting member isrotatable to the back flexion side from the normal state only in a rangeof a predetermined angle (e.g. 45 deg), and thereby, it is free frombottom flexion from the normal state while being able to make backflexion.

When walking on a flat road by using a conventional articulationprosthetic implement, the normal leg is moved a step forward, andsubsequently, the leg on the articulation prosthetic implement is alittle inclined forward [see FIG. 8B] just before the leg on thearticulation prosthetic implement is moved upward, and as a result, thelower articulation protecting member turning to the back flexion sidereturns to the normal state due to the foot weight simultaneously whenthe foot is moved upward, and thereby, it is possible to lessen a chanceof stumbling as compared with the case of a foot tip drooping downward.

However, when walking on a downward slope, it is necessary to rotate thearticulation protecting member at the foot side (lower side) to thebottom flexion side against the articulation protecting member at theleg side (upper side), but in the above configuration, it is unable tomake bottom flexion and the walking is unstable in a bending forwardcondition, and it is sometimes difficult to make a nearly natural walk.Also, as the foot is placed on the ground when walking on an upwardslope, the lower articulation protecting member which supports the footis able to make back flexion, but when the foot being in a state ofbottom flexion is moved up, the lower articulation protecting memberreturns to the horizontal position due to the foot weight, and itsometimes causes the foot tip to touch the downward slope. By changingthe configuration to the one having a rotating angle such that bottomflexion can be made on a downward slope, it is able to walk on adownward slope, but when moving from a downward slope onto a flat roador an upward slope, the configuration is not enough to enable nearlynormal walking, and it is very difficult to handle.

In order to solve the above problem, as a prosthetic implement thatenables nearly natural walking without limitations on bottom flexion andback flexion, in body prosthetic implements having such a configurationthat one body protecting member out of vertically adjoining bodyprotecting members is freely rotatable against the other body protectingmember, well-known is the one provided with a rotating load settingmeans for setting the rotating load to one rotating direction of thefreely rotatable body protecting member greater than the rotating loadto the other rotating direction (for example, refer to the patentdocument 1).

[Patent Document 1) International Publication No. 02/39934 Pamphlet (PCTWO02/39934 A1)

However, the rotary section of the prosthetic implement mentioned in thepatent document 1 has a cross-section as shown in FIG. 19. That is,circular openings 80K are formed at the lower right and left sides oflower thigh rear plate 80, and inner cylindrical member 86 made of metal(it is preferable to use the one made of synthetic resin or the like ifany provided that it has rigidity) which has flange 86A is inserted intoone end of the opening 80K from inside, and the flange 86A and lowerthigh rear plate 80 are fixed with a plurality of screws B80. Also,circular opening 82K is formed at the upper end of foot bottom plate 82,and outer member 87 made of metal (it is preferable to use the one madeof synthetic resin or the like if any provided that it has rigidity)which is externally circular having flange 87A and annular-circulardepression 87B is inserted into the opening 82K from inside, and theflange 87A and foot bottom plate 82 are fixed with a plurality of screwsB82. And, annular one-way bearing 88 as a rotating load setting means isexternally fitted onto circular rotary shaft 87C formed at the center ofouter member 87, and the inner cylindrical member 86 is fitted into theremaining space of depression 87B whose space is partially occupied bythe one-way bearing 88 externally fitted thereon. Also, stopper 89 whichengages projection 87D formed at one end in the axial direction ofrotary shaft 87C is fixed on the projection 87D with one screw B83.

Thus, at the rotating section of the conventional prosthetic implementshown in FIG. 19, lower thigh rear plate 80 must be fixed on flange 86Aat each end of inner cylindrical member 86 by using screws B80, and itis difficult to perform the torque test of rotary joint (theconfiguration of FIG. 19 except lower thigh rear plate 80 and footbottom plate 82).

Also, the rotating load setting means in FIG. 19 comprises outer member87 internally having a circular depression, inner cylindrical member 86having a circular projection which engages the outer member, circularone-way bearing 88 inserted into the portion held between the projectionand depression of the two members, stopper 89 which engages a disk pieceprovided at the one-way bearing and the inner cylindrical member, andscrew B53 which goes through the screw hole provided in the stopper andthe screw hole provided in the outer member. One-way bearing 88 rotatesin one direction, but it does not rotate at all in the other direction(opposite direction) even with a force applied, and regarding theconfiguration of the rotating load setting means, the description is notclear enough to enable the execution of the actual work.

OBJECT AND SUMMARY OF THE INVENTION

The problem to be solved is that it is necessary to build in a lowerthigh rear plate during assembly of a rotary joint, and the rotary jointcannot be assembled and completed beforehand in the form of a singleunit.

In the present invention, the lower thigh rear plate and foot bottomplate of the articulation prosthetic implement can be assembled aftercompletion of the rotary joint assembly, and the rotary joint can beeasily subjected to the torque test in the form of a single unit,thereby enabling the stabilization of load, and this is the mostsignificant characteristic of the present invention.

The articulation prosthetic implement having a rotating load settingmeans of the present invention comprises an outer member (outer housing)with flanges at either end, having an inner rotary shaft and an annulardepression (groove) around the rotary shaft, a one-way clutch forexternally engaging the rotary shaft, a metal bush for externallyengaging the one-way clutch, a synthetic resin bush for externallyengaging the metal bush, a brake bush for externally engaging thesynthetic resin bush, and a cylindrical projection which is fitted inthe annular depression of the outer member located outside the brakebush, wherein the rotary joint having a rotating load setting means isconfigured with an inner member (inner housing) having flanges at eitherend and a stopper mechanism for controlling the range of the rotaryshaft rotation which is installed at the inner projection of the rotaryshaft, and one articulation protecting member of the articulationprosthetic implement is fitted to the flange of the inner member fromthe surface side (foot touching side) of the inner member, and the otherarticulation protecting member of the articulation prosthetic implementis fitted to the flange of the outer member from the surface side(outside) of the outer member.

In this rotary joint, the stopper of the stopper mechanism has aprojection, and the projection is fitted in a long groove provided atthe disk piece of the inner member. Also, the brake bush is made ofsilicone resin.

Also, the articulation prosthetic implement of the present invention isconfigured in that one articulation protecting member is rotatablyconnected via a rotary joint to the other articulation protecting memberadjoining vertically of the articulation, and in the articulationprosthetic implement provided with a rotary joint having a rotating loadsetting means for setting the rotating load to one rotating direction ofthe freely rotatable articulation protecting member larger than therotating load to the other rotating direction, the rotary joint havingthe rotating load setting means has a rotary shaft at the inner side andan annular depression around the rotary shaft, and an outer memberhaving flanges at either end, a one-way clutch for externally engagingthe rotary shaft, a metal bush for externally engaging the one-wayclutch, a synthetic resin bush for externally engaging the metal bush, abrake bush for externally engaging the synthetic resin bush, and acylindrical projection which is fitted in the annular depression of theouter member located outside the brake bush, wherein it is configuredwith an inner member having flanges at either end and a stoppermechanism for controlling the range of the rotary shaft rotation whichis installed at the inner projection of the rotary shaft, and onearticulation protecting member of the articulation prosthetic implementis fitted to the flange of the inner member from the surface side of theinner member, and the other articulation protecting member of thearticulation prosthetic implement is fitted to the flange of the outermember from the surface side of the outer member.

In this articulation prosthetic implement, the stopper of the stoppermechanism has a projection, and the projection is fitted in a longgroove provided at the disk piece of the inner member. Also, the brakebush is made of silicone resin.

In these articulation prosthetic implements, the articulation protectingmember comprises a foot bottom plate which partially or entirelysupports the sole, and a leg protecting plate of which an upperarticulation member partially or entirely protects the leg, and side-endportions where these members are adjoining are connected to each othervia the rotary joint having a rotating load setting means, therebysetting up a lower limb implement.

Also, when walking by using an articulation prosthetic implementprovided with a leg protecting plate and foot bottom plate, the footbottom plate is rotated so that the bottom of the foot bottom plate isparalleled with the ground due to the load applied when the foot bottomplate touches the ground, and the rotating load is set so that the statejust before moving up the foot bottom plate and leg protecting plate ismaintained when the foot bottom plate is moved up.

Also, the leg protecting plate comprises a lower thigh rear plate forprotecting the calf, and the heel-bone part at the rear of foot bottomplate and the Achilles' tendon part at the lower end rear of lower thighrear plate are of open type.

And, the rotational center of the lower thigh rear plate is set to aheight nearly the same as the vertical height position of hominalphysiological foot joint axis. Also, an upper opening and lower openingare formed in the lower thigh rear plate. Also, the right and left frontends of the lower thigh rear plate are provided with a fixing member forfastening and fixing the lower thigh to the lower thigh rear plate,while the right and left ends of the foot bottom plate are provided witha fixing member for fastening and fixing the foot instep to the footbottom plate.

The rotating load setting means comprises a freely rotatable one-wayclutch disposed at the rotary shaft, a metal bush which covers theone-way clutch, a synthetic resin bush which covers the metal bush, anda brake bush which covers the synthetic resin bush.

Also, it comprises a foot bottom plate which partially or entirelysupports the sole, a leg protecting plate which partially or entirelyprotects the leg, and a rotating load setting means provided at therotary shaft of the leg protecting plate in order to maintain the statejust before moving up the foot bottom plate and leg protecting platewhen the foot bottom plate is moved up by rotating the foot bottom plateso that the bottom of the foot bottom plate is paralleled with theground due to the load applied when the foot bottom plate touches theground for walking.

As an articulation prosthetic implement, it comprises a thigh protectingmember which partially or entirely covers the thigh and a lower thighprotecting member which partially or entirely covers the lower thigh,and it is possible to set up a leg implement by connecting the adjoiningsides of these members via a rotary joint having a rotating load settingmeans.

Also, as an articulation prosthetic implement, it comprises an upper armprotecting member which partially or entirely covers the upper arm and afore-arm protecting member which partially or entirely covers thefore-arm, and it is possible to set up an arm implement by connectingthe adjoining sides of these members via a rotary joint having arotating load setting means. Also, in the lower limb implement, it issometimes configured in that the plantar portion is integrally disposedat the bottom of a shoe.

Also, in the method of making (assembling) the articulation prostheticimplement of the present invention, previously manufactured is the onewith a one-way clutch covered and fitted with a metal bush, the metalbush covered and fitted with a synthetic resin bush, and the syntheticresin bush covered and fitted with a brake bush, wherein there areprovided a rotary shaft at the inner side and an annular depressionaround the rotary shaft, and after covering and fitting the rotary shaftof an outer member having flanges at either end with the one-way clutchhaving the three bushes, the cylindrical projection of an inner memberhaving flanges at either end is fitted in the annular depression of theouter member located outside the brake bush, and subsequently, afterscrewing or bolting a stopper for controlling the range of rotary shaftrotation to the inner projection of the rotary shaft, one articulationprotecting member of the articulation prosthetic implement is installedon the flange of the inner member from the surface side of the innermember, and also, the other articulation protecting member of thearticulation prosthetic implement is installed on the flange of theouter member from the surface side of the outer member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view around an articulation prosthetic implementhaving a rotating load setting means in the first embodiment of thepresent invention.

FIG. 2 includes explanatory diagrams of a sectional view showing theoperation mechanism of a one-way clutch. FIG. 2A shows the clutch in astate of being engaged, and FIG. 2B shows the clutch in a state of beingreleased.

FIG. 3 is a front view of an articulation prosthetic implement using arotary joint in the first embodiment of the present invention.

FIG. 4 is a back view of the articulation prosthetic implement shown inFIG. 3.

FIG. 5 is a side view of the articulation shown in FIG. 3, FIG. 4 in astate of being fitted to the lower limb.

FIG. 6 is an explanatory diagram showing the operation of a stopper.FIG. 6A is a front view showing the relations of a stopper and an innermember, and FIG. 6B is an explanatory diagram showing the range ofrotation when the one shown in FIG. 6A is used.

FIG. 7 is an explanatory diagram showing the operation of a stoppergreater in width than the stopper of FIG. 6. FIG. 7A is a front viewshowing the relations of a stopper and inner member, and FIG. 7B is anexplanatory diagram showing the range of rotation when the one shown inFIG. 7A is used.

FIG. 8 shows a state of walking on a flat road with use of thearticulation prosthetic implement in the first embodiment of the presentinvention. FIG. 8A shows a state of walking with the feet arranged inorder. FIG. 8B shows a state of walking with the left foot moved a stepforward. FIG. 8C shows a state of walking just before landing with theright foot stepped forward. FIG. 8D shows a state of walking with theright foot stepped forward and landed.

FIG. 9 shows a state of walking on an upward slope with use of thearticulation prosthetic implement in the first embodiment of the presentinvention. FIG. 9A shows a state of walking with the feet arranged inorder. FIG. 9B shows a state of walking with the left foot moved a stepforward. FIG. 9C shows a state of walking just before landing with theright foot stepped forward. FIG. 9D shows a state of walking with theright foot stepped forward and landed.

FIG. 10 shows a state of walking on a downward slope with use of thearticulation prosthetic implement in the first embodiment of the presentinvention. FIG. 10A shows a state of walking with the feet arranged inorder. FIG. 10B shows a state of walking with the left foot moved a stepforward. FIG. 10C shows a state of walking just before landing with theright foot stepped forward. FIG. 10D shows a state of walking with theright foot stepped forward and landed.

FIG. 11 is a side view of an articulation prosthetic implement in amoderation example of the first embodiment of the present invention.

FIG. 12 is a back view of an articulation prosthetic implement in amoderation example of the first embodiment of the present invention.

FIG. 13 is a perspective view showing a state of an articulationprosthetic implement fitted to an arm in the second embodiment of thepresent invention.

FIG. 14 shows an articulation prosthetic implement in the secondembodiment of the present invention. FIG. 14A is a front view of theimplement, and FIG. 14B is a side view of the implement.

FIG. 15 is a side view showing a state of an articulation prostheticimplement fitted to a leg in the third embodiment of the presentinvention.

FIG. 16 is a front view of the articulation prosthetic implement shownin FIG. 15.

FIG. 17 is a back view of the articulation prosthetic implement shown inFIG. 15.

FIG. 18 is a diagram showing the load setting in the articulationprosthetic implement shown in FIG. 15.

FIG. 19 is a sectional view around a rotary joint of a conventionalarticulation prosthetic implement having a rotating load setting means.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring now to the drawings, some of the preferred embodiments of theinvention are described in detail below.

In the present invention, the purpose of making easier the torque testof a rotary joint or the like has been achieved by using such a methodthat the articulation protecting means is installed after completing therotary joint assembly instead of employing a conventional method inwhich one articulation protecting means is installed during the assemblyof a rotary joint.

The preferred embodiments of the present invention will be described inthe following. The present invention is not limited by the followingpreferred embodiments, and it is preferable to properly change theinvention.

FIG. 1 shows a section around a rotary joint of an articulationprosthetic implement having a rotating load setting means in the firstembodiment of the present invention.

The rotary joint comprises outer member (outer housing) 7 with flanges7A at either end, having rotary shaft 7C at the inner side and annulardepression (groove) 7B around the rotary shaft; one-way clutch 50 forexternally engaging the rotary shaft 7C; metal bush 52 for externallyengaging the one-way clutch 50; synthetic resin bush 54 for externallyengaging the metal bush 52; brake bush 56 for externally engaging thesynthetic resin bus 54; inner member (inner housing) 6 with flanges 6Aat either end, having cylindrical projection 58 which is fitted in theannular depression 7B of the outer member located outside the brake bush56, and a stopper mechanism having stopper 9 or the like for controllingthe range of rotary shaft rotation which is installed at innerprojection 7D of rotary shaft 7C. The rotary joint is formed byassembling these component elements. Reference numeral B3 is a screw orbolt, numeral 70 is a circular groove (see, also, FIG. 7A), and numerals72, 74 are spacers.

And, lower thigh rear plate 1, one articulation protecting member of thearticulation prosthetic implement, is fitted to the flange 6A of innermember 6 of the rotary join assembly from the surface side (right-handside in FIG. 1) of the inner member, and foot bottom plate 2, the otherarticulation protecting member of the articulation prosthetic implement,is fitted to the flange 7A of outer member 7 from the surface side(left-hand side in FIG. 1) of the outer member. Reference numerals B1,B2 are screws or bolts.

Stopper 9 of the stopper mechanism has projection 9B, and it isconfigured that the projection is fitted in long groove 6B provided atthe disk piece of the inner member.

As metal bush 52, for example, the one made of stainless steel is used,and as synthetic resin bush 54, for example, the one made of nylon isused, and as brake bush 56, the one made of silicone resin is used. And,the rotating load can be adjusted by changing the hardness of siliconeresin.

FIG. 2 is an explanatory diagram of a sectional view showing theoperation mechanism of one-way clutch 50. FIG. 2A shows the clutch in astate of being engaged, and FIG. 28 shows a state of the clutch in astate of being released. As shown in FIG. 2A, when outer ring 60 rotatesclockwise against shaft 62, the action of spring 64 causes roller 66 togo to the engaging position of outer ring cam 68 surface, then shaft 62is driven by the wedge effect between outer ring cam 68 surface andshaft 62.

On the other hand, as shown in FIG. 2B, when outer ring 60 turnscounterclockwise against shaft 62, shaft 62 rotates clockwise inrelation to outer ring 60, and roller 66 moves apart from outer ring cam68 surface, then outer ring 60 runs idle against shaft 62. The metalbush 52, synthetic resin bush 54, and brake bush 56 are sequentiallycovered and fitted on outer ring 60, and it is configured in that, evenwhen the clutch shown in FIG. 2A is in engagement, brake bush 56 mayslide on cylindrical projection 58 of inner member 6.

FIG. 3 to FIG. 5 show an articulation prosthetic implement using arotary joint in the first embodiment of the present invention shown inFIG. 1. The articulation prosthetic implement comprises lower thigh rearplate (leg protecting plate) 1 provided with a pair of right and leftextension parts 1A, 1A which are nearly arcuately curved in plan viewfor protecting the calf of the leg and protruded forward for partiallycovering the leg at the upper end side, and two articulation protectingmembers of foot bottom plate 2 nearly U-shaped in front view which isprovided with mount portion 2A having a horizontal surface for placingthe foot (below the ankle) thereon and rise portions 2B, 2B rising fromthe right and left sides of the mount portion 2A, which are maincomponent members, and these vertically adjoining lower thigh rear plate1 and foot bottom 2 are rotatably connected to each other around thecenter of horizontal axis. The lower limb below the knee can be fastenedto the articulation prosthetic implement by two belts 3, 4 shown in FIG.3 to FIG. 5. Each of the fixing members, belts 3, 4, has a surfacefastener which can be steplessly adjusted with respect to the fasteningposition, but it is preferable to have a rubber belt, string and thelike, or it can be omitted when lower thigh rear plate 1 and foot bottomplate 2 are strong enough to hold the lower limb. One end of one belt 3is fixed to the front end at one lateral side of lower thigh rear plate1, and ring-like metal piece 5 (see FIG. 5) for setting the end of belt3 there through is fixed to the front end at the other lateral side oflower thigh rear plate 1. Also, one end of the other belt 4 is fixed tothe upper end at one lateral side of foot bottom plate 2, and hole 2Dfor setting the end of belt 4 there through is formed in the other upperend at the other lateral side of foot bottom plate 2.

Lower thigh rear plate 1 and foot bottom plate 2 are formed from varioustypes of synthetic resin such as polyethylene or these various types ofsynthetic resin partially mixed with other substances such as syntheticrubber or metal so as to provide them with flexibility, thereby enablingthe reduction of their weights, and they have such advantages that thereis no deformation or deterioration due to fatigue in long-time use, andalso, twisting loads from the body during walking can be properlyabsorbed and the original shape can be restored when no load is appliedthereto. It is also possible to use materials other than synthetic resinfor the configuration.

As shown in FIG. 3, the Achilles' tendon part 1B at the rear end oflower thigh rear plate 1 and heel-bone part 2C at the rear of footbottom plate 2 are of open type, thereby enabling the reduction inweight of the entire prosthetic implement and making it easier to wearthe shoe, and also, it is possible to adjust the flexibility of lowerthigh rear plate 1 and foot bottom plate 2. The shoe is omitted in FIG.3 to FIG. 5. Reference numeral 1C shown in FIG. 3 to FIG. 5 is openingformed nearly in the middle vertically of lower thigh rear plate 1,making it possible to reduce the weight of the entire articulationprosthetic implement. The right and left sides at the lower end of lowerthigh rear plate 1 and the right and left sides at the upper end of footbottom plate 2 are rotatably supported by the rotary joint shown in FIG.1.

There is provided a rotary joint having a rotating load setting meansprovided with one-way clutch 50 shown in FIG. 1 to FIG. 3, and thereby,the rotating load against one rotating direction or the direction ofback flexion of foot bottom plate 2 can decreased to zero or almostzero, and also, the rotating load against the other rotating directionor the direction of bottom flexion of foot bottom plate 2 can be set toa level high enough to maintain a state just before lifting the footbottom plate 2 and lower thigh rear plate 1 when foot bottom plate 2 ismoved up. In this way, it assures smooth walking. It is preferable toset the rotating load at any levels provided that the level is highenough to maintain a state just before lifting the foot bottom plate 2and lower thigh rear plate 1 when foot bottom plate 2 is moved up andthat it can be rotated so that the bottom surface of foot bottom plate 2is positioned parallel to or along the ground (surface) due to the loadapplied from the leg when foot bottom plate 2 is landed.

The rotational center X of lower thigh rear plate 1 is, as shown in FIG.5, is set to same height with respect to vertical height position H ofhominal physiological foot joint axis (also called thigh joint axis),and also, it is set to the position intersecting with the vertical lineshown in FIG. 5 or to the position nearly at the center in the forwardand backward direction. Thus, setting the rotational center X of lowerthigh rear plate 1 as shown is most preferable, but setting it to aslightly deviated position is also preferable.

The stopper 9 comprises, as shown in FIG. 6A, disk piece 9A forslide-guiding in circular groove 70 of inner member 6 along with therotation of inner member 6, and projection 9B of nearly trapezoidal inshape protruding partially axially of the outer periphery of disk piece9A. Also, long groove 6B is formed in the peripheral direction ofcylindrical member side edge (axial inner side edge) of flange 6A ofinner member 6, and projection 9B is getting into the long groove 6B.Accordingly, foot bottom plate 2 is able to rotate 20 degrees to thebottom flexion side [angle range of C1 shown in FIG. 6A, FIG. 6B] and 45degrees to the back flexion side [angle range of D1 shown in FIG. 6A,FIG. 6B] from a state of the foot joint set at 0 degree, that is thestate (shown by solid line) where foot B and leg A are nearly 90 degreesto each other as shown in FIG. 6B. Notches 6 b, 6 c arcuately formedtoward the axially outer side are formed at both ends of long groove 6B,thereby enabling smooth rotation at both ends even when long groove 6Bis not accurately formed up to each end.

Also, as shown in FIG. 7A, the size (width size) in the peripheraldirection of projection 9B of stopper 9 is larger (wider) than stopper 9shown in FIG. 6A, and foot bottomplate 2 is able to rotate 45 degrees[angle range of D3 shown in FIG. 2A, FIG. 7B] only to the back flexionside from a state of the foot joint set at 0 degree as described above.Thus, it is possible to properly change the length of long groove 6B andthe width of projection 9B.

The movable range of a human leg joint is less than 45 degrees withrespect to both of bottom flexion and back flexion (sometimes less than35 degrees), and by setting the rotational angle to 45 degrees asdescribed above, it is possible to obtain a state equivalent to beingfree without limitation on angle for a human body. Also, it is sometimesnecessary to change the limitation on angle according to the degree(level) of the symptom of clubfoot, but there is no problem even whenexecuted in a completely free state with stopper 9 omitted.

Described in the following is the case of walking with an articulationprosthetic implement configured as described above fitted to an affectedpart. First, in walking on a flat road where the ground is horizontal,as shown in FIG. 8A, when the normal left foot is moved a step forwardfrom a state with the normal left foot and the right foot on theprosthetic implement arranged in order as viewed from side, the rightleg A at the implement side is inclined 15 degrees [angle of E1 in FIG.8B] from its vertical position, as shown in FIG. 8B. In this case, sincethe rotating load to the back flexion side is zero or almost zero, lowerthigh rear plate 1 is able to smoothly rotate to the angle of leg A.Subsequently, when the right foot on the prosthetic implement is raisedfrom the ground to move a step forward, then as shown in FIG. 8C, theright foot can be moved while maintaining the position (with the rightleg A inclined 15 degrees forward from the vertical position) justbefore raising, and the right foot tip will not droop forward to touchthe ground. And, when the right foot heel is landed on the ground, footbottom plate 2 rotates 15 degrees [angle of E2 in FIG. 8D] to the bottomflexion side due to the load then applied, and the position is changedso that the bottom surface of foot bottom plate 2 is paralleled with theground surface.

Described next is the case of walking on an upward slope (ascent). Asshown in FIG. 9A, when the normal left foot is moved a step forward froma state with the normal left foot and the right foot on the prostheticimplement arranged in order as viewed from side or more in detail from aposition with the leg inclined 15 degrees forward [angle of F1 in FIG.9A] to any foot from the vertical position, the right leg A at theimplement side is inclined 15 degrees more from the position inclinedforward to take a position inclined 30 degrees forward [angle of F2 inFIG. 9B], as shown in FIG. 9B. In this case, since the rotating load tothe back flexion side is zero or almost zero, the lower thigh rear plate1 is able to smoothly rotate to match the angle of leg A. Subsequently,when the right foot on the prosthetic implement is raised from theground to move a step forward, then as shown in FIG. 9C, the right footcan be moved while maintaining the position (with the right leg A,inclined 30 degrees forward) just before raising, and the right foot tipwill not droop forward to touch the ground. And, when the right footheel is landed on the ground, foot bottom plate 2 rotates 30 degrees[angle of F3 in FIG. 9D] to the bottom flexion side due to the load thenapplied, and the position is changed so that the bottom surface of footbottom plate 2 is paralleled with the ground surface.

Finally described is the case of walking on a downward slope. As shownin FIG. 10A, when the normal left foot is moved a step forward from astate with the normal left foot and the right foot on the prostheticimplement arranged in order as viewed from side or more in detail from aposition with the leg inclined 15 degrees backward [angle of G1 in FIG.10A] to any foot from the vertical position, the right leg A at theimplement side is inclined forward from the position inclined backwardto take a position vertical to the ground, as shown in FIG. 10B. In thiscase, since the rotating load to the back flexion side is zero or almostzero, the lower thigh rear plate 1 is able to smoothly rotate to matchthe angle of leg A. Subsequently, when the right foot on the prostheticimplement is raised from the ground to move a step forward, then asshown in FIG. 10C, the left foot can be moved while maintaining theposition (with the right leg A vertical to the ground) just beforeraising, and the right foot tip will not droop forward to touch theground. And, when the right foot heel is landed on the ground, footbottom plate 2 rotates 30 degrees [angle of G2 in FIG. 10D] to thebottom flexion side due to the load then applied, and the position ischanged so that the bottom surface of foot bottom plate 2 is paralleledwith the ground surface.

FIG. 11 is a side view of an articulation prosthetic implement in amoderation example of the first embodiment, and FIG. 12 is a back viewof the same. In this moderation example, in the first embodiment, theportion below outer member 7 is provided one-piece with shoe 15.

In this moderation example, belt 4 that is the fixing member shown inFIG. 3 to FIG. 5 is omitted since the foot is secured by front leatherpart 17 and tongue leather part 16 of shoe 15. Also, it is preferable toprovide front leather part 17 with a string or flexible rubber in orderto secure the instep. Also, rise portion 2B is previously provided alonginner portion 18 in the shoe. Similarly, mount portion 2A is integralwith inner bottom 12 in the shoe or sole 11. In this case, the mountportion can be fixed with screw or the like.

The other parts are substantially same as in the first embodiment, andthe description is omitted. In this moderation example, the portionformed one-piece with the shoe is a portion generally below the calf,but it is preferable to properly adjust the shape of extension part 1Aor lower thigh rear plate 1 in accordance with the type and use of theshoe. Also, it is preferable to provide an opening for adjustment in theshoe for the purpose of adjusting the rotating load adjusting means.

When the person wears a shoe after installing the first embodiment,since the shoe is tight for the thickness of heel-bone part 2C and mountportion 2A, and in addition, the shoe is separate from the prostheticimplement, it causes inconvenience in taking exercise. In thismoderation example, since the extension part and the mount portion arestored in the shoe, it will lessen the sense of incongruity when takingexercise or the like. Also, outer member 7 is stored in the shoe, and itwill bring about an advantage that the connections are protected.

FIG. 13, FIG. 14A and FIG. 14B show an articulation prosthetic implementin the second embodiment of the present invention.

Articulation prosthetic implement 20 comprises plate 21 having a pair ofright and left extension parts 21A, 21A for protecting the rear of theupper arm, and forearm plate 22 having a pair of right and leftextension parts 22A, 22A similarly for protecting the rear of theforearm, which is arcuately curved. These upper arm and forearm plates21, 22 are rotatably connected to each other about the center of thehorizontal axis nearly from the elbow cell to the elbow. In this case,the outer member 7 and the inner member 6 are connected by connectionmember 25A for upper arm plate 21 and connection member 25B for forearmplate 22. And, the two connection members 25A, 25B are secured by screw29 to plates 21, 22, respectively.

Also, the upper arm and forearm can be fastened to the prostheticimplement 20 by means of four belts 23A to 23D disposed in theprosthetic implement 20. The fixing members, belts 23A to 23D can besteplessly adjusted with respect to the fastening position the same asfor fixing belts 3, 4 described in the first embodiment. The number offixing members is not always necessary to be four, and it is preferableto have a rubber belt, string and the like provided that prostheticimplement 20 can be fixed. It is also preferable to use metal piece 5 orthe like although it is not shown in the figure.

Also, plates 21, 22 for the upper arm and the forearm are respectivelyprovided with openings 27, 28 nearly at the back of the upper arm andthe back portion of the forearm, thereby realizing the weight reduction.The other parts are substantially same as in the first embodiment, andthe description is omitted.

Prosthetic implement 20 of this embodiment realizes a prostheticimplement suited for the user because the load setting can be properlyadjusted unlike a plaster cast or the like which simply fixes the arm.

FIG. 15 to FIG. 18 show an articulation prosthetic implement in thethird embodiment of the present invention. FIG. 15 is a side view ofprosthetic implement 30 of this embodiment. Prosthetic implement 30comprises thigh plate 31 having a pair of right and left extension parts31A, 31A for protecting the rear of the thigh, and lower thigh plate 32having a pair of right and left extension parts 32A, 32A similarly forprotecting the rear of the thigh, which are arcuately curved. Theselower thigh and thigh plates 31, 32 are rotatably connected to eachother about the center of the horizontal axis nearly from. the knee cellto the knee. In this case, the outer member 7 and the inner member 6 areconnected by connection member 37A for thigh plate 31 and connectionmember 37B for lower thigh plate 32. And, the two connection members37A, 37B are secured by screw 29 to plates 31, 32, respectively. Also,the lower thigh and the thigh can be fastened to prosthetic implement 30by means of five belts 33A to 33E disposed in the prosthetic implement30. Also, the adjustment can be made by using metal piece 5 or the likealthough it is not shown in the figure. Plates 31, 32 for the thigh andthe lower thigh are respectively provided with openings 35, 36 nearly atthe back of the thigh and around the calf, thereby realizing the weightreduction.

For example, in prosthetic implement 30 as shown in FIG. 18, when theknee flexes in one rotating direction R1, it is set so that the rotatingload is nearly zero, and when it flexes in the other rotating directionR2, it is set so that the rotating load is greater than the load indirection R1. According to the setting, for example, when walking up thesteps, with the foot at the normal side used as a support, the foot onprosthetic implement 30 at the opposite side is raised, then. the loadin direction R1 is zero, and therefore, the knee can be naturally flexedenough to go up the steps as the thigh flexes. Subsequently, until thefoot on prosthetic implement 30 reaches the next step according to themovement of weight supported by the foot at the normal side, the angleof the knee can be maintained at the position since the load in rotatingdirection R2 is set greater. After the movement of weight, the footwearing the prosthetic implement 30 reaches the surface of the step,then the prosthetic implement 30 is rotated by a part of the loadapplied to the knee.

By using prosthetic implement 30 of the third embodiment as describedabove, even when the load applied to one knee as in going up the stepsis greater than that applied thereto in walking on a flat road, it ispossible to realize a prosthetic implement which may support the walkand absorb the shocks.

Also, it is preferable to put the embodiment 1 on the ankle and to usethe third embodiment 3 on. the knee. The other parts are substantiallysame as in the first embodiment, and the description is omitted.

Also, the prosthetic implement of the present invention can be appliedto a joint connection for a wrist, shoulder and the like besides theabove example, and it is possible to properly change the shape of theprosthetic implement and the specific configuration.

The manufacturing (assembling) method for the articulation prostheticimplement of the present invention will be described in the followingwith respect to the embodiment shown in FIG. 1 to FIG. 5. Previouslymanufactured is the one with one-way clutch 50 covered and fitted withmetal bush 52, the metal bush 52 covered and fitted with synthetic resinbush 54, and the synthetic resin bush 54 covered and fitted with brakebush 56. And, there are provided rotary shaft 7C at the inner side andannular depression 7B around the rotary shaft, and after covering andfitting the rotary shaft 7C of outer member 7 having flanges 7A ateither end with one-way clutch 50 having three bushes 52, 54, 56, thecylindrical projection 58 of inner member 6 having flanges 6A at eitherend is fitted in the annular depression 7B of the outer member locatedoutside the brake bush 56. Subsequently, stopper 9 for controlling therange of rotation of the rotary shaft is screwed or bolted to innerprojection 7D of rotary shaft 7C.

Thus, after assembling the rotary joint having a rotating load settingmeans, lower thigh rear plate 1 that is one articulation protectingmember of the articulation prosthetic implement is fitted to flange 6Aof inner member 6 from the surface side (right-hand side in FIG. 1) ofthe inner member, and foot bottom plate 2 that is the other articulationprotecting member of the articulation prosthetic implement is fitted toflange 7A of outer member 7 from the surface side (left-hand side inFIG. 1) of the outer member. Reference numeral 1K is a groove forfitting the lower end opening of lower thigh rear plate 1 therein, andnumeral 2K is a groove for fitting the upper end opening of foot bottomplate 2 therein.

In the present invention, since the single unit of a rotary joint can bepreviously assembled and completed, it is possible to easily execute thetests such as a torque test with a rotary joint unit and to stabilizethe load, thereby improving the assembling method and the workingefficiency. Also, as an independent product in the form of a rotaryjoint unit, it enables the manufacture of special items.

Also, according to the present invention, setting the rotating load tothe bottom flexion side greater than the rotating load to the backflexion side, when raising the landed foot, it can be maintained by thearticulation prosthetic implement to the angle of the foot just beforeraising, and therefore, the foot tip will not droop downward to touchthe ground simultaneously when the foot is raised, and also, it can beeasily and smoothly turned to the back flexion side. Also, since theload of a part of weight applied with the foot landed is converted intoa rotating force for rotating the articulation protecting member, evenwhen the rotating load is set greater, it is possible to smoothly rotatethe articulation protecting member to execute bottom flexion that usedto be impossible. Accordingly, it is possible to provide an articulationprosthetic implement which enables almost natural walking while makingsmooth bottom flexion and back flexion in any places (varying roadconditions) as in walking on slopes (upward and downward), waking from aflat road to a slope or from a slope to a flat road as well as walkingon a flat road.

Also, according to the present invention, setting the rotating load to alevel such that the load applied with the foot bottom plate landedcauses the foot bottom plate to be rotated and paralleled with theground surface, and the state just before raising the foot bottom plateand the leg protecting plate can be maintained, it is possible to avoidstumbling due to the foot touching the slope when the foot is raised,and also, when the foot bottom plate is landed, the load (a part ofweight) applied with the foot landed causes the foot bottom plate tosmoothly rotate, and thereby, it is possible to make an articulationprosthetic implement which is easier to handle.

Also, according to the present invention, since the heel-bone part atthe rear of the foot bottom plate and the Achilles' tendon part at thelower end rear of the lower thigh rear; plate which are free fromproblems with respect to strength are of open type; it is possible toreduce the weight and to make easier to wear a shoe. Also, theflexibility of the foot bottom plate and the lower thigh rear plate canbe adjusted, and it is possible to configure an articulation prostheticimplement suited for patents.

Also, according to the present invention, setting the rotational centerof the lower thigh rear plate to a height nearly the same as thevertical height position of hominal physiological foot joint axis, therotational center of the foot joint axis and lower thigh rear plate canbe made nearly equal to the rotational center of the foot bottom plate,and it is possible to configure an articulation prosthetic implementwhich allows the foot joint axis of a human body to move easily and iseasier to handle.

Also, according to the present invention, since an opening is formed ina vertical middle portion of the lower thigh rear plate, the weight canbe further reduced, and also, the flexibility can be improved, and it ispossible to configure an articulation prosthetic implement most suitedfor any patents.

Also, according to the present invention, since there is provided afixing member for fixing a human body to the lower thigh rear plate orthe foot bottom plate over the right and left front ends of the lowerthigh rear plate or the right and left upper ends of the foot bottomplate, it is possible to avoid removal of the articulation prostheticimplement during walking, thereby bringing about an advantage such thatsmooth walking is realized.

Also, according to the present invention, since the rotating loadsetting means is configured with a one-way clutch and bush disposed onthe rotary shaft of the articulation protecting member, the rotatingload to one side (e.g. to the back flexion side) can be eliminated asmuch as possible, and the rotating load to the other side (e.g. to thebottom flexion side) can be set to a level such that the foot bottomplate is not rotated by the weight of the foot placed on the foot bottomplate, and thereby, it is possible to assure further natural (smooth)walking.

Also, according to the present invention, since the rotating load to oneside (e.g. to the back flexion side) can be eliminated as much aspossible, and the rotating load to the other side (e.g. to the bottomflexion side) can be set to a level such that the foot bottom plate isnot rotated by the weight of the foot placed on the foot bottom plate,and thereby, it is possible to provide an articulation prostheticimplement which may assure further natural walking without limitationson bottom flexion and back flexion.

Also, it is preferable to use a configuration with this inventioninstalled in a shoe. Since the mount portion and the like are housed inthe shoe, it is possible to provide an articulation prosthetic implementwhich may stand use for taking exercise or the like.

Also, according to the present invention, it is possible to configure aprosthetic implement with the protecting plates for upper arm andforearm connected to each other by the rotating load setting means. Inthis configuration, setting one rotating load greater than the otherrotating load, it is possible to provide a prosthetic implement for theelbow according to the condition of the user.

Also, according to the present invention, it is possible to configure anarticulation prosthetic implement with the protective plates for thethigh and the lower thigh connected to each other by the rotating loadsetting means. In this configuration, setting one rotating load greaterthan the other rotating load, it is possible to provide a prostheticimplement for the knee which may properly compensate for the flexion ofthe knee in going up and down the steps or the like and preventaccidents such as stumbling.

Having described preferred embodiments of the invention with referenceto the accompanying drawings, it is to be understood that the inventionis not limited to those precise embodiments, and that various changesand modifications may be effected therein by one skilled in the artwithout departing from the scope or spirit of the invention as definedin the appended claims.

1. A manufacturing method for an articulation prosthetic implementhaving a rotating load setting means, comprising the steps of previouslymanufacturing a one-way clutch covered and fitted with a metal bush, themetal bush covered and fitted with a synthetic resin bush, and thesynthetic resin bush covered and fitted with a brake bush, and coveringand fitting a rotary shaft of an outer member with flanges at eitherend, having a rotary shaft at the inner side and an annular depressionaround the rotary shaft, with the one way clutch having the threebushes, followed by fitting a cylindrical projection of an inner memberhaving flanges at either end into the annular depression of the outermember located outside the brake bush, subsequently screwing or boltinga stopper for controlling the range of rotary shaft rotation to an innerprojection of the rotary shaft, fitting one articulation protectingmember of the articulation prosthetic implement to the flange of theinner member from the surface side of the inner member, and fitting theother articulation protecting member of the articulation prostheticimplement to the flange of the outer member from the surface side of theouter member.